New EjectOnDeath system.

This new EjectOnDeath system allows for vehicles (aircraft or ground units) to eject a PilotActor with a percent SuccessRate upon death.

This also eliminates the MinimumHeight check that is currently being used, and replaces it with two booleans;
PilotEjectOnGround: yes/no
PilotEjectInAir: yes/no
It is possible to have both set to yes/true with the result being as expected.

In defaults.yaml:
^Vehicle and ^Tank have a 20% chance to eject an e1 while OnGround.
^Plane has a 50% chance to eject an e1 while InAir.

This is my first contribution so I am very excited for it and hope it comes in handy for someone (along with being accepted and merged)!